The present disclosure relates to a fuel tank vent system, and particularly, to vent apparatus which operates to seal the vapor space in the interior region of a fuel tank during refueling and reopens at some point after refueling has been completed to vent the vapor space. More particularly, the present disclosure relates to a float-actuated fill-limit valve included in a tank-mounted vent apparatus.
Management of fuel vapor onboard a vehicle is an important part of modern vehicle fuel system design. A fuel tank vent system selectively discharges pressurized fuel vapor from a fuel tank in response to rising levels of liquid fuel in the fuel tank during fuel tank refueling and also during development of high tank pressure conditions. Buoyant float valves often are used to close vent outlets in fuel tank vent systems because they are able to float on liquid fuel as it rises in a fuel tank that is being filled with fuel discharged by a fuel-dispensing pump nozzle and thus move upwardly on the rising liquid fuel in the fuel tank to close a vent outlet when the tank is filled with fuel.
Fuel-dispensing pump nozzles are known to include a fill-limiting sensor for shutting off the flow of fuel from the nozzle when the fuel tank is nearly filled. Typically, this fill-limiting sensor is triggered whenever the fuel tank is full and fuel “backs up” the filler neck to splash onto or reach the fill-limiting sensor located on the nozzle.